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Background Hypotension is common after cardiac arrest (CA), and current guidelines recommend using vasopressors to target mean arterial blood pressure (MAP) higher than 65 mmHg. Pilot trials have compared higher and lower MAP targets. We will review the evidence on whether higher MAP improves outcome after cardiac arrest. Methods This systematic review and meta-analysis will be conducted based on a systematic search of relevant major medical databases from their inception onwards, including MEDLINE, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL), as well as clinical trial registries. We will identify randomised controlled trials published in the English language that compare targeting a MAP higher than 65-70 mmHg in CA patients using vasopressors, inotropes and intravenous fluids. The data extraction will be performed separately by two authors (a third author will be involved in case of disagreement), followed by a bias assessment with the Cochrane Risk of Bias tool using an eight-step procedure for assessing if thresholds for clinical significance are crossed. The outcomes will be all-cause mortality, functional long-term outcomes and serious adverse events. We will contact the authors of the identified trials to request individual anonymised patient data to enable individual patient data meta-analysis, aggregate data meta-analyses, trial sequential analyses and multivariable regression, controlling for baseline characteristics. The certainty of the evidence will be assessed by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. We will register this systematic review with Prospero and aim to redo it when larger trials are published in the near future. Conclusions This protocol defines the performance of a systematic review on whether a higher MAP after cardiac arrest improves patient outcome. Repeating this systematic review including more data likely will allow for more certainty regarding the effect of the intervention and possible sub-groups differences. Sigrid Juselius Stifelse [8050]; Academy of Finland [341277]

Occult cerebral ischemia is one likely contributor to the development of hypoxic ischemic brain injury in patients after cardiac arrest. Local brain hypoxia may occur, irrespective of significant hypotension, especially if autoregulation of cerebral blood flow (CBF) is impaired. The regional brain saturation of oxygen (rSO2) may be estimated non-invasively, using near infrared spectroscopy (NIRS). The rSO2 also offers a surrogate measure of CBF and makes it possible to estimate the efficacy and limits of cerebrovascular autoregulation by calculating the moving correlation in the time domain between arterial pressure and rSO2. The advantage of NIRS is its easy implementation, providing continuous data. Studies have not, thus far, shown unequivocal associations between the rSO2 estimates of autoregulation and the magnitude of hypoxic ischemic brain injury or the clinical neurological outcome. With the use of invasive catheters inserted through a cranial burr hole, the partial pressure of oxygen in brain tissue (PbtO2) can be measured directly—as can intracranial pressure (ICP), local blood flow and markers of metabolism. Such catheters are commonly used in neurointensive care, but less so in the management of cardiac arrest patients. This is due to the risk of bleeding complications associated with anticoagulation and antiplatelet therapy, which is standard practice in cases where the cause of the arrest is myocardial ischemia. Pilot studies have shown promise—both for the use of PbtO2 and for its potentially superior precision over NIRS in detecting brain ischemia. The means available for treating cerebral ischemia include manipulating the arterial blood pressure with vasopressors, as well as modifying blood oxygen and carbon dioxide levels by adjusting ventilatory management. Thus far, no conclusive evidence exists supporting these interventions to alleviate hypoxic ischemic brain injury and improve outcome. One possible strategy is the adoption of a multimodal treatment strategy to detect and treat cerebral ischemia—similar to the management of patients with TBI.

To discuss recent findings relevant to optimizing blood pressure targets in adult, postcardiac arrest (PCA) patients and whether to tailor these based on specific patient, cardiac arrest or treatment characteristics.Observational data suggest that mean arterial pressure (MAP) below 65-75 mmHg in PCA patients is associated with worse outcome. A higher MAP could be beneficial in patients with chronic hypertension who more frequently have a right shift of the cerebral autoregulation curve. Two recent randomized pilot trials compared lower and higher MAP targets during PCA care and found no significant effect on biomarkers of neurological injury. The haemodynamic interventions in those studies did not use any cerebral perfusion endpoints beyond a static MAP targets during ICU stay. Individualized, dynamic MAP targets based on assessments of cerebral perfusion and tailored to the specifics of the patient, cardiac arrest circumstances and treatment responses may be more conducive to improved outcomes. Pilot data suggest that near infrared spectroscopy monitoring may be used to determine the cerebral autoregulatory capacity and an optimal MAP, but this approach is yet to be tested in clinical trials.Current evidence suggests targeting a MAP of at least 65-75 mmHg in PCA patients. Future studies should focus on whether certain patient groups could benefit from higher and dynamic MAP targets.

OBJECTIVE: To identify reliable predictors of outcome in comatose patients after cardiac arrest using a single routine EEG and standardized interpretation according to the terminology proposed by the American Clinical Neurophysiology Society.METHODS: In this cohort study, 4 EEG specialists, blinded to outcome, evaluated prospectively recorded EEGs in the Target Temperature Management trial (TTM trial) that randomized patients to 33°C vs 36°C. Routine EEG was performed in patients still comatose after rewarming. EEGs were classified into highly malignant (suppression, suppression with periodic discharges, burst-suppression), malignant (periodic or rhythmic patterns, pathological or nonreactive background), and benign EEG (absence of malignant features). Poor outcome was defined as best Cerebral Performance Category score 3-5 until 180 days.RESULTS: Eight TTM sites randomized 202 patients. EEGs were recorded in 103 patients at a median 77 hours after cardiac arrest; 37% had a highly malignant EEG and all had a poor outcome (specificity 100%, sensitivity 50%). Any malignant EEG feature had a low specificity to predict poor prognosis (48%) but if 2 malignant EEG features were present specificity increased to 96% (p < 0.001). Specificity and sensitivity were not significantly affected by targeted temperature or sedation. A benign EEG was found in 1% of the patients with a poor outcome.CONCLUSIONS: Highly malignant EEG after rewarming reliably predicted poor outcome in half of patients without false predictions. An isolated finding of a single malignant feature did not predict poor outcome whereas a benign EEG was highly predictive of a good outcome.

Introduction: Prolonged time to Return of Spontaneous Circulation (ttROSC) after Out of Hospital Cardiac Arrest (OHCA) has consistently been associated with adverse outcome by a plausible direct relation to severity of anoxic injury. Hypothesis: Target temperature management (TTM) is assumed effective against anoxic brain injury and we hypothesized that TTM at 33 degrees would be more beneficial with prolonged time to ROSC compared to 36 degrees. Methods: In a post hoc analysis of the TTM trial, which showed no overall benefit of targeting 33 °C over 36 in 939 patients (NEJM 2013), we investigated the relation of time to ROSC and mortality and neurological outcome as assessed by the Cerebral Performance Category (CPC) and Modified Ranking Scale (mRS) after 180 days. Results: Prolonged ttROSC was significantly and independently associated with increased mortality, pinteraction =0.85. In survivors prolonged ttROSC was associated with increased odds of surviving with an unfavorable neurological outcome for CPC (p=0.008 for CPC 3-4) and a similar trend, albeit not statistically significant was observed for mRS (p=0.17, mRS 4-5). Odds for unfavorable neurological outcome (CPC>2, mRS>3) was not modified by levels of TTM overall. Conclusion: Time to ROSC remains a significant prognostic factor in comatose patients resuscitated from OHCA with regards to risk of death and risk of adverse neurological outcome in survivors. TTM at 33 degrees offers no advantage over targeting 36 degrees with regards to mortality or neurological outcome in patients with prolonged time to ROSC. Figure: Mortality rates stratified by quartiles of tome to ROSC and by TTM level. Differences tested by log rank test in between TTM in strata

Traditionally, Scandinavian anaesthesiologists have had a very broad scope of practice, involving intensive care, pain and emergency medicine. European changes in the different medical fields and the constant reorganising of health care may alter this. Therefore, the Board of the Scandinavian Society of Anaesthesiology and Intensive Care Medicine (SSAI) decided to produce a Position Paper on the future of the speciality in Scandinavia. The training in the various Scandinavian countries is very similar and provides a stable foundation for the speciality. The Scandinavian practice in anaesthesia and intensive care is based on a team model where the anaesthesiologists work together with highly educated nurses and should remain like this. However, SSAI thinks that the role of the anaesthesiologists as perioperative physicians is not fully developed. There is an obvious need and desire for further training of specialists. The SSAI advanced educational programmes for specialists should be expanded and include formal assessment leading to a particular medical competency as defined by the European Union of Medical Specialists (UEMS). In this way, Scandinavian anaesthesiologists will remain leaders in perioperative, intensive care, pain and critical emergency medicine.